Novel compositions for polyurethane coatings



United States Patent US. Cl. 260-47 6 Claims ABSTRACT OF THE DISCLOSURENovel compositions for preparing flexible polyurethane coatings having ahigh chemical and mechanical resistance comprised of a polyisocyanateand a hydroxyl containing component formed by addition of a phenolcompound to a compound selected from the group consisting of anunsaturated alcohol having 10 to 48 carbon atoms and adducts thereofwith ethylene oxide or propylene oxide and the polyurethane coatingsproduced therewith.

PRIOR ART The use of lacquers comprised of polyvalent isocyanates andpolyesters having free hydroxy groups prepared by esterification ofdicarboxylic acids with dior trihydroxy alcohols as protective coatingsfor a wide variety of materials is well known. However, the coatingsprepared from these lacquers have various disadvantages in theirresistance to hydrolysis due to the presence of the ester group.Lacquers comprised of polyvalent isocyanates and polyglycol ethers forforming coatings are also known but these coatings are also susceptibleto aqueous chemical solutions.

Also, it is known that lacquers, stable at room temperatures, can beobtained from the reaction of an organic polyisocyanate with analiphatic, cycloaliphatic or araliphatic monoalcohol and a polyamide,but such lacquers do not have any self-crosslinking, cold-hardenablecoating agent. Air-drying lacquers derived from diisocyanates andunsaturated monoalcohols are also known, but these lacquers have to behardened with the addition of specific organometallic compounds. In thelast two instances, no compounds "containing several hydroxyl groups areused. Finally, coating agents comprised of polyisocyanates and shortchain alcohols such as butanediol and decamethyleneglycol are also knownbut these lacquer compositions are only slowly-hardenable at roomtemperature which is undesirable and therefore have to be hardened atelevated temperatures.

OBJECTS OF THE INVENTION It is an object of the invention to providenovel lacquer compositions for forming polyurethane coatings which havea high chemical and mechanical resistance.

It is another object of the invention to provide novel coatingcompositions which have a sufiiciently long potlife but are hardenableat room temperature within a relatively short time.

It is a further object of the invention to provide objects with apolyurethane coating which have a high chemical and mechanicalresistance.

These and other objects and advantages of the inven- 3,523,100 PatentedAug. 4, 1970 ice tion will become obvious from the following detaileddisclosure.

THE INVENTION The novel compositions of the invention useful forpreparing polyurethane coatings having a high chemical and mechanicalresistance are comprised of an organic polyisocyanate and a hydroxylcontaining compound selected from the group consisting of an adduct of aphenol and unsaturated, straight and branched chain fatty alcohols of 10to 48 carbon atoms, condensation products thereof with an alkylene oxideselected from the group consisting of ethylene oxide and propylene oxideand an adduct of a phenol with the condensation product of unsaturated,straight and branch chain alcohols of 10 to 48 carbon atoms and analkylene oxide selected from the group consisting of ethylene oxide andpropylene oxide in an inert organic solvent. When ethylene oxide andpropylene oxide condensation products are used an excess ofpolyisocyanate is recommended, the ratio of isocyanate groups tohydroxyl groups being 1.0 to 2.5.

The hydroxyl containing adducts can be advantageously prepared byreacting phenols or phenol-derivatives with unsaturated, straight orbranched chain alcohols having 10 to 48 carbon atoms, or theiralkoxylated derivatives in the presence of acid aluminum silicates ascatalysts at a temperature of -250 C. Particularly suitable catalystsare aluminum silicates, activated with mineral acids and having apH-value of 3-5 and the said silicates are used in an amount of 1-15% byweight of the reaction mixture. It is to be noted that if there areseveral double bonds in a straight carbon chain of the alcohol moleculeand an excess of the phenol is used, only one mol of phenol is addedonto this carbon chain. For branched chain products, such as Guerbetalcohols, one mol of phenol can be added to each individual carbon chainas long as the branched chains contain double bonds.

-Suitable phenol compounds are such phenols or substituted phenols whichcan be alkylated due to the presence of at least one exchangeablehydrogen atom on the aromatic ring. Examples of suitable phenols arephenol, polyhydroxyphenols such as pyrocatechol, pyrogallol,hydroquinone; alkylated phenols such as cresols, xylenols; halogenatedphenols; naphthols such as anaphthol; and phenols having severalaromatic rings such as Bisphenol A, o,o'-diphenol, etc.

The unsaturated alcohols of 10 to 48 carbon atoms may be monoorpoly-unsaturated. Examples of suitable alcohols are unsaturated fattyalcohols such as decenol, dodecenol, hexadecenol, octadecenol or oleylalcohol, octadecadiene 9,12 01 or linolenylalcohol, octadecatriene-9,12,15-01 or linolenyl alcohol, etc. Particularly useful areunsaturated fatty alcohols derived from natural waxes or fromunsaturated fatty acids of natural oils and fats which may be in pureform or mixtures. Examples of said alcohols are Sojacenol obtained byhydration of soy bean oil while preserving the double bonds which ispredominantly unsaturated C13 alcohols and Leinocenol obtained byhydration of linseed oil while preserving the double bonds. Alsosuitable are guerbet alcohols of monoor polyunsaturated fatty alcoholsor mixtures thereof and particularly unsaturated alcohols derived fromnatural waxes or unsaturated fatty acids of natural fats and oils by theguerbet reaction such as guerbet alcohols of Sojacenol calledSojaguerbet alcohol or of Leinocenol called Leinguerbet alcohol. Alsouseful are the condensation products of the said alcohols with l to 6moles of ethylene oxide and/ or propylene oxide.

with 1 to 6 moles of ethylene oxide and/or propylene oxide which has theadvantage of simultaneously vary ing the degree of flexibility andincreasing the chemical resistance of the final polyurethane coatings.Preferably,

pending-upon the selection of the 'polyisdcyana'te" coinon n n i r, cemqn s. they h n a mom tem erament about 1 4 hours in'a' dist-dry marineThe lacquer layers obtain their final hardness in about 3-5 days. Ofcourse, the hardening process can be efthe hydroxyl containing adductsare condensed with 1 to 5 fected at elevated temperature in acorrespondingly 6 mols of propylene oxide. High molar ratios ofpropylshorter time. ene oxide results in decreased chemical resistance.The The compositions of the invention provide well adhersaidcondensation products can be prepared by conden sing coatings with avarying flexibility depending upon ing a few moles of alkylene oxidewith the unsaturated 10 use on metals, wood, rubber, plastics, textiles,paper etc. fatty alcohol, reacting the condensation product with the Thecoatings display outstanding abrasion resistance'and phenol andcondensing a few more moles of the alkylgloss and uniform coverage and aremarkably high resistene oxide with the resulting hydroxyl containingadduct. 7 ance to hydrolyzing chemicals such as aqueous alkaline Thehydroxyl containing adducts should'be as free as solutions. Thecompositions which contain a-hydroxyl possible of non-reacted phenols orunsaturated fatty alcontaining adduct condensed with ethylene loxid'eand cohols since the said starting materials disrupt chainforparticularly propylene oxide have simultaneously a,,very mation andthus impair the preparation of the high 1110- high chemical resistanceand good;flexibilit y,.

' lecular weight polyurethanes. Preferably the said adducts In thefollowing examples, there are described several are the sole hydroxylcontaining ingredient in the mixpreferred embodiments t'o illustrate-theinvention. Howture, although up .to 10% by weight of other known hyever,it should be understood that the invention is" not droxyl compounds suchas trimethylolpropane, glycol, intended to be limited to the specificembodiments. glycerine, etc., used in polyurethane coatings may be A Ladded thereto. Preferably 0.5 to 1.5% by weight of tri-. EX MP ESmethylol propane i u d The adducts of a phenol and an unsaturated.alcohol The organic polyisocyanate used in the compositions of Tablelwer P p in the wi g nllflf lh are well known aliphatic and aromatic diorpolyisocyphenol and unsaturated alcohol were introduced mto a anates andtheir adducts with polyvalent low molecular r actlon vessel providedwith. a stirrer, a thermometer weight alcohols. Examples of suitablepolyisocyanates n a reflux n n r 19 the a 0 n shown in are hexamethylenediisocyanate, toluylene diisocyanate, Table I with 10% by we1gl1t of T 31 L80 a;cor nn 1 e'rp,p'-diphenyl diisocyanate, p,p'-diphenylmethanediisocy- 1 1 fullefs earth havlflg 3 P 0f p u yd e anate, p-phenylenediisocyanate, p,p',p"-triphenylmethat 120. C. for 3 hours as a catalyst.The resulting reacane triisocyanate and adducts thereof such as 3 molsof n n ix r W heated to the temperature q njn toluylene diisocyanatewith 1 mole of trimethylolpropane. Table I for 4 hours under anatmosphere of nitrogen The compositions are preferably prepared bydissolvand with vigorous stirring. The "reaction mixture was ing thehydroxyl containing adduct in an inert organic then cooled to 100 C. andthe catalyst was removed solvent such as ethyl acetate, benzene,toluene, Xylene, th r r m by Vacuum filtration The fii d Pi methylenechloride, dioxane, diacetate of ethylene lyand unsaturated alcohols weredistilled oif up' toa'temcol, etc., and then adding the desired amountof polyisoperature of 190 at 0.01 torr and the residue wast-he cyanate.Depending upon the specific components and desired adduct having thehydroxylnumber given in Table the use of the final coating,stoichiometric, slight excess 40 I. The p r nt yield Was based ononemo'le of phenol to or slight deficiency of the polyisocyanate isused. An exbe added to each unsaturated hydrocarbon chain 'which cess ofpolyisocyanate is preferred with alkylene oxide means that for a 100%yield one mole of the phenol is condensation products. The rate of thehardening procadded to each unsaturated hydrocarbon chain I? 7 TABLE IStarting materials Reaction H Molar tempera- Hydroxyl Percent PhenolAlcohol ratio aturefC. No. yield 1 Oleyl alchoL. an 160 5276' 92 2Sojaocenol. 3:1 163 p 268 H 92 3.- do Leinocenol 3:1 180 277 77 4.-a-Naphthol. Sojaocenoh 3:1 160 L220 71 5 2-hydroxyphenoL. d0 3:1 160e30. ,100 6.. o-chlorophenol ..d0 311 165474 246 .42 7 Phenoxyethanol..d0 3:1 160 236 8 l-phenoxy loxypropand "do-" 3:1 160 24! 71 9o,o-Diphenol .do 3:1 160 423 78 l0 Phenol Sojaguerbet alcoho 6:1 160 110'83 ll Leinguerbet alcohol-.- 6:1 170 156 52 lla p-Cresol, Sojaocenol3:1 165 226 72 11b Phenol Oleyl alcohol plus 1 3:1 .f.

mole of propylene oxide.

Several of the phenolralcohol addilct of 'lable Tfwjere furthercondensed with 'ethyleneoxide'or' propylene oxide according to thefollowing procedure. -The adducts were reacted at C. with sufiicientmethanol solution containing 30% sodium niethylafeto have} 0.2%" by'Weight of sodium for the said adduct. The res'nltingjcleari warmsolution was heated at 60 C. under vacuumdo distilloff the methanol andthen heated in an autoclave'undera nitrogen atmospher'to the reaction tepe ature saowa in Table I I'. Then the'alkylene oxide was aaaea' in thet'riolar as zinc chromate, titanium dioxide, talc, etc. The compositionscan be applied to dry surfaces to be coated by spraying, painting ordipping in the usual manner. De

ratios of Table II under a pressure of'abo utb' atmospheres after whichthe alkoxylated produt was neutralized with concentrated "formic acidand vacuum filtered while hot to remove the precipitated sodiumfo'rma'te;

The adducts of Tables 1 and II were then dissolved in anhydrous ethylacetate with or without the trime'thylolpropane having a hydroxyl numberof 1,219 and/or triethylamine indicated in Table III. The said solutionswere The mechanical properties of all the clear films as determined bytheir tensile strength, impact resistance, elongation and abrasion wassatisfactory and did not difier noticeably.

then reamed will} the isocyanate solutiofls fld Z in Isocyanate solutionA of Table III was a 75% solution Table m Obtaln lacquer Soluuon and theof the adduct of toluene diisocyanate and trirnethylolpro- Sultmgsohmons gf g 2 l f 1% hours pane in a 3:1 molar ratio which is soldunder the name roozn f i z i f er g :f Desmodur L75 and isocyanatesolution N of Table III a 1 :2 gg pfs j i resulting: filgms is asolution of the condensation of hexamethylene were remyoved from thePlates and stored for days at 20 dusocyanate wlth water in a 3:1 molarratio which is sold 50 C. Each of the films prepared from thecompositions under the name Desmodur of the invention were clear, hardand flexible. The che'rn- The results are reported Table In and thevalues ical resistance of the films was determined by hanging-m6 used toreport the results have the following definitions: strips in water, a20% aqueous sodium hydroxide solution 30 U unchan ed and 20% aqueoushydrochloric acid at C. For coml k parative purposes, films wereprepared from compositions 01.5 using as the hydroxyl containingcompounds, Desmophen W=takes on a Whlte color 800 (polyester of adipicacid, phthalic acid and a trihy- Z=becomes decomposed droxy alcoholhaving a hydroxyl number of 298) and 35 desmophen 1100 (polyester ofadipic acid, butylene glycol and diand trihydroxyl alcohols having ahydroxyl num- +++=mtense her of 220). ++++=very intense TABLE IIIlliplar} Cl m ca Time in solution I8 10 0 l8 Examples-Lacquercomposition NCO: 0H Pot life resistance 5 15 30' 1 h. 3 h. 5 h.

I Hlo. U U U U U U (1) 5 g. Desmophen 800, 10g. isooyanate Solution A; 9ethylaceta'lel iile fiiii i if 1:213:13::::::::::::::::::::::

H2O U W+ W+ W+ W+ W+ (2) 5 g. Desmophen 1100, 7.5 g. isooyawesome A; 9ethylaceme- "{Ebilli'ltii F i i i I:::::::::::::::::::::::::::::::

U U U (3) 2.5g.adduot No. 12, 3.0g. isocyanate solution A; 4.5 g.ethylacetate. w++++ "i:

(4) 23.7 g. edduot No. 13; 1.3 g. trimeth- H O U U U U U .Ympmpane byweight); 3&0 1. an a days {NaO 1i 2 0 7 I I U U U w+ w U gsgztgagatesolution A; 45 g. ethyl- HO% F+ F+ F+ F+ III:

(5) g. adduatgNg. 14; 0.l1tg. grgmeth- H20 U U Y Pmpane Y 1. 6:1 4 days..{Naon 207 U w++ w+++ w++++ gsiate solution A, 4.5 g. ethylace- Ho 0 F+F++ F++ (6) 2.5 g.adduct No.15; 3.5 g.isocyanate H O U U solution A; 3.5ethylacetate; 1 g. 2 U 0.01% triethylam ine solution in ethm 14 i Wi+++yl acetate (0.001% by weight).

O U U U U (7) 2.5 g .adduot No. 16; 2.6 g.1socyanate 2 s0lut1onA;4.5g.ethylacetate. idays %g:: g El wi+++ III:

n20 U U U U U (8) 2.5 g adduct N0. 18, 2.5g.1s00y3118l78 L 5:1 2% days20 w+ w+ w+ w+ W solution A; 4.5 g. ethylaoetate. j F+ F+ F+ F++ ii'III:

(9) 2.5 g. adduct No. 19; 2.0 g. iso- HZO U U U U oyanate solution A;4.5 g. ethyl- 1.5:1 1% day NaOH U W+ W++ W+++ acetate. HCI F+ F+ F+ (10)2.5 g. adduct No. 18; 2.5 g. isooyanate solution A; 3.5 g. ethyl- U U UU acetate; 1 g. 0.1% triethylarulne solu- U U W++ W++ tion inethylacetate (0.01% by F-l- F+ F+ weight).

(11) 2.5 g. adduct No. 17; 2.2 g. lsocya- H2O U U U U nate solution A;3.5 g. ethylacetate; 1 842 hours fi U U w+ w 1 g. 0.17 triethylamine insolution in ethylacgtate (0.01% by weight). H01 20% F+ F+ F+ TABLE IIIMolar y h V, A. Timeinsolutlun is, A ratio 01 Chemical Examples-Lacquercomposition NCO: H Pot life resistance 6' 15' 30' 1 h. 3 h. 5 11.

12 mg. No. 14; 2.6 g. lsocyanate solu- U tion N; 4.0 g. ethylacetate;0.8 g. 1% (1 U U U U trietliylamine solution in ethyl- 9 N30 W U U U U Wacetate (0.1% by weight). 39 2%---.---, U U U m0 U o U U U 'U (13) 1.8g. adduct No. 14, 3.0 g. isocyanate solution N; 4.0 g. ethylacetate. 4?g g g g g g 2 U o .Q'U o w W (14) 2.5 g. adduct No. 8 4.1 g. lsocyanatesolution A; 4.5 etliylacetate. 5 g? g g g (15) 2.5 g. adduct No. 3.45 g.isocyanatesolutlon A; 3.5 g. ethylacetate; 1 21 1 day g 3 5+ -Fi- 1 g.0.01% triethylamlne solution in H012, U U U UH g ethyla'cetate (0.001%by weight), a w

H O U U v U W W+ w++ (10) 2.5 g. adduct N0. 21, 3.55 g. isoy eyantesolutionA;4.6g.etl1ylaeetate. 1 day gg fi V g g g Y We claim:

1. A composition for preparing polyurethane coatings havingja highchemical and mechanical resistance comprisingj an organic polyisocyanateand a hydroxyl containing compound selected from the group consisting ofan adduct of a phenol and unsaturated straight and unsaturated branchedchain fatty alcohols of 10 to 48 carbon atoms, condensation productsthereof with 1 to 6 moles of an alkylene oxide selected from the groupconsisting of ethylene oxide and propylene oxide and an adduct of aphenol with the condensation product of unsaturated straight andunsaturated branched chain alcohols of 10 to 48 carbon atoms and l to 6moles of an alkylene oxide selected from the group consisting ofethylene oxide and propylene oxide, in an inert organic solvent.

2. The composition of claim 1 wherein the unsaturated fatty alcohol isselected from the group consisting of unsaturated fatty alcohols derivedfrom natural fats, oils and waxes and condensation products thereof withl to 6 moles of an alkylene oxide selected from the group consisting ofethylene oxide and propylene oxide.

3. The composition of claim 1 wherein the unsaturated fatty alcohol isselected from the group consisting of unsaturated guerbet alcohols andcondensation products thereof with 1 to 6 moles of an alkylene. oxideselected froiln the group consisting of ethylene oxide and propylene one. I

4. The composition of claim 1 which also contains 0.5 to 1.5% by Weightof total mixture of trimethylolpropane.

5. The composition of claim 1 which also contains 0.001 to 0.1% byweight of the total. mixture of triethylamine catalyst. p

6. A polyurethane coating having a high chemical and mechanicalresistance formed by applying a composition of claim 1 to a substrataand curing the said composition.

References Cited UNITED STATES PATENTS 9/1968 Sutker et a1 260- WILLIAMH. SHORT, Primary Examiner I L. L. LEE, Assistant Examiner US. Cl. X.R.

